Total alkaline phosphatase. All about lowering alkaline phosphatase in the blood

In the process of diagnosing diseases of internal organs, it is rarely possible to do without laboratory tests. By determining the biochemical composition of blood, it is possible to give an objective assessment of the patient’s health status. A standard diagnostic test includes a blood test for a substance called alkaline phosphatase. In what pathologies is the concentration of this substance reduced?

Violations of the functions of certain internal organs cause changes in the composition of the blood. For this reason, diagnosis cannot be done without biochemical tests. One of the substances whose content is determined in the blood during a standard examination is alkaline phosphatase. Let's look at what it is and what a decrease in enzyme activity indicates.

What is it?

The term alkaline phosphatase (for brevity, many sources use the designation ALP) is used to designate a group of enzymes whose main function is to ensure the occurrence of dephospholation processes.

This reaction involves the separation of the phosphate group from organophosphorus compounds. Phosphatase acts as a reaction catalyst, that is, it ensures the occurrence of metabolic processes of calcium and phosphorus.

Advice! The enzyme received the name alkaline phosphatase because it is active only in an alkaline environment (pH level 9-10). There is also acid phosphatase, but other methods are used to determine its blood level.

This enzyme is found in different tissues, so several isoforms are isolated. However, there are mainly two isoforms present in the blood, one of them is found in liver tissue, the second in bone cells.

Indications

The reasons for changes in the level of alkaline phosphatase in the blood are varied; most often, its concentration changes when:

pathological processes in the liver and gall bladder;
the appearance of tumor diseases;
lesions of the skeletal system and injuries (fractures);
infectious mononucleosis and cytomegalovirus infection;
pregnancy.

Therefore, determination of the concentration of the enzyme alkaline phosphatase is prescribed if the patient complains:

for weakness, indigestion, change in urine color (darkening), itching;
for frequent fractures, bone pain, bone deformities;
during routine examinations of people working in hazardous industries;
during routine examinations during pregnancy.

Advice! Such an analysis can be prescribed not only during the diagnostic process, but also during treatment. Evaluation of indicators allows one to judge the effectiveness of the prescribed treatment and control the spread of the pathological process.

Procedure

As with any blood test, you need to properly prepare for the ALP test.

The preparation rules for all biochemical analyzes are the same:

at least one day before collecting materials, you must exclude alcohol and fatty foods;
On the morning of donating blood, you should skip breakfast and only drink a little water.

Advice! It must be remembered that the level of alkaline phosphatase enzyme is influenced by taking many medications, including hormonal contraceptives. Therefore, it is important to warn the doctor that the patient is taking any medications.

Evaluation of results

A specialist must decipher the results of the analysis, since even if deviations from the norm are identified, it is impossible to make a diagnosis based on the results of one analysis.

Normal indicators

The normal level of concentration of the enzyme alkaline phosphatase varies widely. The norms differ for people of different ages. In children, enzyme levels are always significantly higher than in adults.

It affects the assessment of results and the gender of the patient, as well as some physiological conditions. Thus, during pregnancy the level of the placental fraction of the enzyme increases and this is the norm.

In addition, the standards depend on how the analysis was carried out. The fact is that different laboratories use different reagents, so the reference values can vary significantly. The range of indicators that represent the norm must be indicated on the laboratory form.

What does a decrease in concentration indicate?

If the analysis revealed that alkaline phosphatase is contained in a concentration that is significantly lower than accepted standards, then it will be necessary to determine the causes of this condition. Possible reasons for such analysis results may include the following conditions:

recent significant blood transfusion;
severe anemia;
insufficient nutrition, unbalanced diet, resulting in a deficiency of zinc and magnesium in the body;
vitamin deficiency, a decrease in enzyme levels is observed with a deficiency of vitamins B12 and C.

Low levels of this enzyme in children are often caused by congenital syndromes that lead to impaired bone growth. An example of such a pathology is achondroplasia. With this disease, there is a deformation of the spine and too short limbs with a normal body size.

Bone growth disorders, accompanied by a decrease in alkaline phosphatase levels, are also observed in some other congenital syndromes, in particular Down syndrome. Another hereditary syndrome characterized by low levels of alkaline phosphatase in the blood is hypophosphatasemia.

With this disease, calcification of bone tissue is impaired. A feature of this disease is that with a reduced level of alkaline phosphatase in the blood and bone tissue, there is no decrease in the level of elements such as phosphorus and calcium.

A common cause of decreased alkaline phosphatase levels is hypothyroidism. With this disease, the functions of the thyroid gland are disrupted, as a result of which the synthesis of hormones is reduced. This affects many processes in the body, including metabolic ones.

Normally, the level of alkaline phosphatase in pregnant women should increase, this is due to the formation of the placenta. Therefore, if the enzyme concentration is significantly lower than normal, then this is a rather alarming sign. Such test results may indicate placental insufficiency. With this pathology, the normal nutrition of the fetus is disrupted, which can lead to delays in its development.

Timely detection of placental insufficiency allows for the necessary treatment and reduces the risk of negative consequences.

What to do?

If it turns out that the level of alkaline phosphatase is reduced, there is no need to try to diagnose yourself. The analysis is not specific; additional examinations will be required to determine the cause of the decrease in the concentration of the enzyme in the blood.

Therefore, the correct action plan would be:

You should consult a therapist with the results of the analysis;
undergo examinations prescribed by the doctor;
if necessary, seek advice from specialists.

Only after the cause of the decrease in ALP levels has been established and a diagnosis has been made, treatment can begin.

So, an analysis for the content of the enzyme alkaline phosphatase can be prescribed in the process of diagnosing a number of diseases, as well as during treatment to evaluate the prescribed therapy. To correctly assess the decrease in the level of this enzyme in the blood, a specialist will need to study data from other examinations.

It should be remembered that the range of normal phosphatase levels is quite wide, and the reasons leading to changes in enzyme concentration are varied. Therefore, even an experienced doctor will not be able to make a diagnosis based on one analysis. Moreover, you should not try to do it yourself.

Alkaline phosphatase is one of the elements of blood biochemistry. This term refers to a set of isoforms that are detected in all organs.

There are 11 isoforms in total, the most important of which are the isoforms of the liver and bone tissue, because these forms are found in the blood in greater quantities than isoforms of other organs, which determines their organ specificity for enzyme diagnostics. Blood is taken for analysis during liver tests, as well as when a diagnosis has already been made to determine the effectiveness of treatment.

What is alkaline phosphatase and what does it show?

What is alkaline phosphatase? It is an enzyme that catalyzes the reactions of cleavage of phosphoric acid residues from phosphorus-containing organic compounds of the bone matrix, resulting in an increase in the concentration of phosphates, which contributes to the formation of hydroxyapatites and the formation of crystallization centers. It also has transferase activity, transferring phosphorus residues to organic compounds, phosphorylating or dephosphorylating, thus changing the activity of other enzymes involved in the mineralization of bone tissue.

It exhibits maximum activity at the stage of bone mineralization, at pH = 9.6 (therefore, this phosphatase is alkaline).

This enzyme is considered one of the main markers of liver pathology. It is excretory and increases in the blood when the gland is inflamed due to obstructed blood outflow. It is produced by hepatocytes, and in bone tissue the enzyme is produced by osteoblasts.

ALP in a biochemical blood test is represented predominantly by liver and bone isoforms, the activity of which in the body is higher compared to other isoforms.

ALP norm

The normal level of alkaline phosphatase in the blood is from 44 to 147 IU/l. This indicator can vary greatly, depending on gender, age, and laboratory. Therefore, it is important to compare your result with the standards of the laboratory in which the blood test was performed.

The reason for the change in enzyme levels may be the condition of the person being tested. For example, in the blood of a pregnant woman or an actively growing teenager, the level of the enzyme will be higher than normal, which will not be a sign of the disease.

The level of alkaline phosphatase in children of different ages will have their own norms, which differ from adults:

children under 10 years old - from 150 to 350 IU/l;
children from 10 to 19 years old - from 155 to 355 IU/l;

It is elevated due to the predominantly bone isoform, which is secreted by osteoblasts. This is due to enhanced processes of bone formation and mineralization. If the child’s test result is less than 150 IU/l, which is the norm for an adult, it means that bone formation processes are less active than they should be.

A blood test for alkaline phosphatase is taken on an empty stomach; you should not smoke 30 minutes before the test. Blood is taken from a vein.

Reasons for the increase

The normal indicators for women and men are different, which is important to consider when deciphering the analysis results:

alkaline phosphatase, the norm in women is from 35 to 105 IU/l;
the norm for men is from 40 to 140 IU/l.

In addition to gender, age also affects enzyme levels. It is important to consider that ALP levels are higher in children than in adults. This is normal and is not a sign of pathology.

The indicator should be increased in pregnant women, which is associated with the active development of the placenta. In this case, a decrease in the enzyme in the blood will indicate the presence of problems in the woman’s body. Such a decrease in enzyme levels is dangerous due to the possibility of underdevelopment of the placenta, which can lead to involuntary abortion.

In adults, the increase in the enzyme occurs mainly due to the liver isoform, which indicates the presence of inflammation of the gland. During inflammation, the outflow of the enzyme from the organ is difficult, so it diffuses into the blood. Rarely, the enzyme content increases due to an increase in the bone isoform in the blood.

Reasons why alkaline phosphatase is elevated:

In addition to increased activity, an alkaline phosphatase test can also show reduced enzyme activity.

Reasons why alkaline phosphatase is low:

Anemia or severe anemia.
Transfusion of a large volume of blood.
Hypothyroidism is a decrease in the activity of the thyroid gland. In adults, this condition manifests itself as myxedema.
Scurvy is a disease associated with a decrease in vitamin C levels. Ascorbic acid is a coenzyme of lysyl and prolyl hydroxylases, which are involved in the synthesis of collagen. Due to improper collagen synthesis, bone tissue mineralization processes are disrupted.
Deficiency of vitamin B6, which is a coenzyme of lysyl oxidase.
Menopause - decrease in estrogen.
Hypophosphatosia is a hereditary disease that leads to softening of bone tissue.
Deficiency of Zn and Mg.
Osteoporosis.
Donation.
Starvation.

How to bring the indicator to normal?

A change in the level of an enzyme is almost always a consequence of some pathology in the body, therefore, to normalize the indicator, it is necessary to detect the disorder in which organ led to the changes and eliminate the problem.

But alkaline phosphatase can change in healthy people due to several reasons:

When using hormonal drugs, alkaline phosphatase levels may change. Their abolition can normalize the enzyme level. To do this, you must consult a doctor.
Aspirin, allopurinol (used to treat gout), paracetamol and antibiotics can increase enzyme levels, which is not a cause for concern because stopping these drugs will return the levels to normal.

If an increase or decrease in the level of alkaline phosphatase is not caused by taking any drugs, but is a consequence of diseases, then changes in the indicator will help specialists diagnose the pathology and prescribe the correct treatment, and the indicators will return to normal after treatment.

Therefore, regular examination is so important for the timely detection of pathologies that can have dangerous consequences.

Alkaline phosphatase is one of the indicators included in the list of parameters of a biochemical blood test.

In this article, we will determine what values for this indicator are considered normal, how to properly prepare for the test, and consider the main reasons why alkaline phosphatase is elevated or decreased.

Alkaline phosphatase (ALP) is an enzyme that speeds up chemical reactions. It plays a key role in transporting phosphorus across the cell membrane. This is one of the main regulators that is responsible for the exchange of phosphorus and calcium. ALP is present in all tissues of the human body in varying concentrations. Its maximum content is found in the liver, bile ducts, bone tissue, kidneys, and intestines.

The peak activity of this substance occurs when it enters conditions of high alkali content. In the blood of a healthy person, the enzyme is present in minimal quantities and does not show its activity. If there is a blockage of the biliary tract, or disruption of the normal functioning of the gallbladder or liver, then alkaline phosphatase accumulates in the body, entering the bloodstream.

Based on the level of alkaline phosphatase, many pathologies that disrupt the functioning of the liver and biliary system can be diagnosed. And also the activity of the enzyme is overestimated when the metabolism of phosphorus and calcium is disrupted, which leads to destruction and deformation of bones, slowing down the restoration processes of the skeletal system.

Normal values

The generally accepted ALP norm based on traditional testing methods may differ from the values obtained in some laboratories.

This is due to the fact that enzyme activity is determined using non-traditional laboratory methods, and the biomaterial is incubated at different temperatures.

Therefore, when determining normal values for alkaline phosphatase, it is best to focus on the reference values of a particular laboratory indicated in the analysis results form. The generally accepted unit of measurement for ALP is the international unit of activity (ME or U) per liter (l).

In adult men and women

The general norm of alkaline phosphatase for an adult under 50 years of age falls within the range of 20 to 130 ME/l.

However, when considering the enzyme norm taking into account age categories and gender, the lower limit of the range increases. On average, the level of alkaline phosphatase in men is 10-30 units higher.

The table shows values that reflect the normal level of alkaline phosphatase, differentiated by age and gender:

In children

Alkaline phosphatase activity in children will be significantly higher than in an adult, and this is normal. The child is in a continuous process of growth, all organs and systems develop throughout childhood until the end of adolescence.

During this time, the complete formation of the skeletal system, the formation of hormonal levels, and puberty occur.

The norm of alkaline phosphatase from the neonatal period to adulthood:

In the first weeks after birth, the enzyme level in a baby can reach up to 400 U/l; in premature babies this value is much higher - up to 1000 U/l. This is due to a more intensive process of development of organic and bone tissues.
By the age of one year and up to 3 years, the ALP value can range from 350 to 600 U/l.
From 3 to 9 years – from 400 to 700 U/l.
From 10 to 18 years, ALP ranges from 155 to 500 U/l. During puberty, its concentration can reach the highest values and amount to 800 - 900 U/l. This is due to the fact that the teenager’s body undergoes serious changes associated with the increased production of its own hormones that regulate all metabolic processes.

During pregnancy

During pregnancy, ALP levels will be higher than normal. This is explained by the fact that in a woman’s body, starting from the second week after conception, the placenta actively develops, which contains a large amount of this enzyme.

A rapid increase in placental ALP values is observed in the third trimester, shortly before the birth of the child, when the placenta reaches the peak of its maturity.

At this time, the ALP content is twice the maximum level of a healthy non-pregnant woman.

Table of norms of placental alkaline phosphatase in accordance with trimesters of pregnancy:

A significant excess of the indicated norms indicates an unfavorable course of pregnancy - the development of a severe form of gestosis.

A reduced level of alkaline phosphatase in the body of a woman expecting a child may mean the development of placental insufficiency, and should be a reason to check the degree of maturity of the placenta. Data on the level of alkaline phosphatase in a pregnant woman has important diagnostic value.

Correct interpretation of the results of a biochemical blood test allows you to identify serious complications and take corrective action in a timely manner.

Preparation for analysis and its implementation

The ALP test is performed by collecting venous blood from the patient. To determine the concentration of the enzyme in the resulting biological material, a chemical method called colorimetry and a set of reagents are used.

To obtain a reliable result, you should follow simple recommendations before donating blood:

It is better to donate blood early in the morning, on an empty stomach. The fasting period should be at least 8-10 hours and no more than 14, while drinking water without gas is allowed.
The day before donating blood, you should avoid physical activity and intense training.
Avoid drinking alcohol two to three days before the test.
The emotional state should be calm; if possible, limit exposure to factors that cause a stress reaction.
If you smoke, refrain from smoking before donating blood. The break should be at least half an hour.
Warn your doctor about the medications you took a couple of days before the test.

In the forms of results of biochemical blood tests, ALP is designated by the common abbreviation ALP. An additional letter after this designation will indicate the place where this enzyme fraction was formed. For example, ALPI - in the intestines, ALPL - in the tissues of the liver, bones, kidneys, or it is also called nonspecific alkaline phosphatase, ALPP - in the placenta.

When detecting deviations of the alkaline phosphatase level from the norm, the following indicators are additionally analyzed to clarify the reasons:

ALT and AST enzymes;
bilirubin;
balance of calcium and phosphorus;
GGTP or GGT.

The price of an analysis (in 2018) to determine the level of alkaline phosphatase in Moscow, excluding the cost of the blood collection procedure, averages 250 - 270 rubles.

What causes the increase?

For example:

bone growth due to age-related reasons;
formation of new bone tissue after injuries;
puberty, hormonal “changes”;
age-related degenerative-dystrophic processes in the bone structure;
intensive sports training;
vitamin deficiency as a result of poor nutrition and dieting;
alcohol and nicotine addiction;
excess weight, excess fat deposits;
low physical activity;
excess vitamin C;
taking medications containing acetylsalicylic acid, paracetamol, as well as medications classified as antibiotics;

protection from pregnancy by taking oral contraceptives;

taking drugs that have a negative toxic effect on liver tissue (sulfonamides, methotrexate, tetracycline).

An increase in alkaline phosphatase levels in women does not necessarily indicate diseases of the internal organs. There are two main physiological causes that are not caused by any pathology - pregnancy and lactation.

However, enzyme values above normal often signal the presence of serious diseases. In severe forms of pathologies, the level of alkaline phosphatase can reach up to 2000 U/l.

Diseases that provoke a sharp increase in alkaline phosphatase levels form three conditional groups.

Pathologies of the liver and biliary tract

This enzyme is considered a marker of bile stagnation, which is observed in the following ailments:

cholestasis;
cholangitis;
liver cirrhosis (its biliary variant);
infectious mononucleosis;
hepatitis of various origins (viral, drug, toxic);
oncological diseases of the liver and biliary tract;
the formation of stones blocking the outflow of bile;
mechanical, cholestatic jaundice (due to long-term use of female sex hormones).

Bone damage

The enzyme is actively produced in osteoblasts - new bone-forming cells that arise from the destruction of old ones. The higher their activity, the more pronounced the concentration of alkaline phosphatase will be.

Among the diseases that destroy bone tissue are:

Paget's disease (inflammatory skeletal damage);
osteomalacia (deviation in the process of mineralization, leading to unnatural flexibility, fragility and softness of bones);
osteosarcoma (malignant lesion of bone-forming cells).

Other diseases

A large number of diseases affecting various body systems cause an increase in ALP:

pathologies of the cardiovascular system - chronic heart failure, myocardial infarction, damage to cardiac muscle tissue;
hormonal disorders - hyperthyroidism (thyrotoxicosis), pathologies of the adrenal glands (hyperfunction), hyperparathyroidism (Burnet's syndrome), diffuse toxic goiter (Graves' disease);
congenital disease of the urinary system (osteonephropathy or “renal” rickets);
rickets in children of the first year of life caused by a lack of vitamin D;
miliary tuberculosis;
pathologies of the gastrointestinal tract - the formation of through damage in the wall of the stomach, cancer of the gastrointestinal tract, nonspecific ulcerative colitis (UC), inflammatory process of the intestinal mucosa (Crohn's disease);
malignant lesions of the blood (leukemia), lymphatic tissue (lymphoma);
inflammation of the internal genital organs, ovarian, endometrial, cervical cancer;
damage to bone marrow cells (multiple myeloma) and others.

What causes the decline?

A decrease in ALP levels in the blood may indicate that there are diseases in the body that require treatment:

deficiency of thyroid hormones (hypothyroidism), as a consequence, the development of myxedema (mucoedema), retardation in mental and physical development (cretinism);
severe anemia;
intestinal enzymopathy (celiac disease, celiac disease);
congenital anomalies of skeletal development (achondroplasia, hypophosphatasia).

In addition, ALP may be underestimated as a result of:

deficiency of vitamins – groups C and B (B6, B9, B12);
lack of elements - zinc and magnesium;
excess vitamin D;
severe dystrophy due to protein deficiency (kwashiorkor);
donor blood transfusion, coronary artery bypass surgery;
placental insufficiency during pregnancy;
menopause;
taking hormonal medications containing estrogen.

Among the cardiovascular causes of decreased alkaline phosphatase, chronic heart failure is common, leading to enlargement of the heart chambers and their pathological expansion.

Along with low ALP levels, high cholesterol levels, tachycardia and blood vessel diseases are often diagnosed.

Conclusion: if the alkaline phosphatase level is above 150 U/l, you should pay attention to the state of your own health, especially if you already have chronic diseases of the liver and biliary tract.

The following symptoms may indicate a metabolic disorder: nausea, feeling tired, fatigue, poor appetite, joint pain, unpleasant aching sensations in the area under the right hypochondrium. If pathologies are excluded, then it is worth retaking the test a week after the first test, and following all recommendations regarding preparation for the test procedure.

Alkaline phosphatase(wrong spelling alkaline phosphatase) is an enzyme involved in the transport of phosphorus through the cell membrane and is an indicator of phosphorus-calcium metabolism. Alkaline phosphatase is found in bone tissue, intestinal mucosa, liver hepatocytes, renal tubular cells and placenta. The main volume of alkaline phosphatase is located in the intestinal mucosa (the content of alkaline phosphatase in the intestine is 30–40 times higher than in the tissue of the liver and pancreas and 100–200 times higher than in the salivary glands, gastric mucosa, and bile). Alkaline phosphatase is produced by the surface layer of the intestinal mucosa, but its role in digestion is secondary. Its main functions are related to the processes of general metabolism.

To diagnose various diseases and conditions, a study of alkaline phosphatase is performed in blood serum, urine, intestinal juice, feces, and alkaline phosphatase isoenzymes are determined: liver, bone, intestinal, placental, Regan and Nagayo isoenzymes in blood serum, in amniotic fluid .

Chemically, alkaline phosphatase is a group of isoenzymes, phosphohydrolases of orthophosphoric acid monoesters, having a molecular weight of 70 to 120 kDa, hydrolyzing phosphoric acid esters in the range from 8.6 to 10.1 pH. Code of alkaline phosphatase as an enzyme, EC 3.1.3.1.

Analysis of small intestinal juice for alkaline phosphatase

Determination of alkaline phosphatase activity in the juice of the small intestines is used to assess the functional state of the intestinal mucosa. Alkaline phosphatase is determined separately for the duodenum and jejunum. The level of alkaline phosphatase in duodenal juice is approximately 10–30 units/ml. For residents of the south, the activity of alkaline phosphatase in intestinal juice is slightly higher than for those living in the north. The activity of alkaline phosphatase in jejunal juice ranges from 11 to 28 units/ml (average 19.58±8 units/ml). To study the enzyme secretory function of the small intestine, it is preferable to study juice from more distal parts of the small intestine, where this enzyme is usually more abundant.

Alkaline phosphatase activity is considered normal in the range from 10 to 45 units/ml. An increase in alkaline phosphatase activity in duodenal juice from 46 to 100 units/ml is considered weak, from 101 to 337 units/ml is considered significant, over 337 units/ml is considered as sharp. The activity of alkaline phosphatase may depend on the nature of the diet, which reduces the diagnostic value of determining alkaline phosphatase in intestinal juice (Sablin O.A. et al.).

Determination of alkaline phosphatase in stool analysis

Alkaline phosphatase is examined during a general clinical analysis of stool. In this case, the norm is:

in adults - from 45 to 420 units/g
in children - from 327 to 9573 units/g

Increased activity of alkaline phosphatase is observed in enterocolitis, acute intestinal diseases accompanied by diarrhea.

Professional medical literature regarding the role of alkaline phosphatase in gastroenterology

Sablin O.A., Grinevich V.B., Uspensky Yu.P., Ratnikov V.A. Functional diagnostics in gastroenterology. Educational and methodological manual. – St. Petersburg. - 2002. – 88 p.

Vasilenko V.V. Interpretation of liver test results // Medical Bulletin. Clinician school. – 2011. - No. 5 (546).

Normal alkaline phosphatase levels in biochemical studies

Constant time method (in μkat/l): men 0.9–2.3, women 0.7–2.1, children under 14 years of age 1.2–6.3
Kinetic method with LACHEMA reagent (in IU/l): adults - up to 120, children - up to 250, newborns - up to 150
Kinetic method with KONE reagent 80–295 U/l

Serum alkaline phosphatase

Despite the presence of various isoforms of alkaline phosphatase in body tissues, more than two or three isoforms are rarely detected simultaneously in blood serum. Isoforms of alkaline phosphatase, found in the blood serum of patients with various diseases, retain characteristics characteristic of isoforms found in the liver, bone tissue, intestinal mucosa, and placenta. In the blood serum of a healthy person, the liver and bone isoforms of alkaline phosphatase are most often found.

The activity of alkaline phosphatase depends largely on the age and, to a lesser extent, on the gender of the patient. It, in particular, increases during puberty and intensive growth of bone tissue. Currently, there is no standardized method for determining the activity of alkaline phosphatase in blood serum; specific numbers may differ slightly depending on the reagents used and the research method. Below are the reference values of alkaline phosphatase activity using the IFCC method at 30 C in units/l (M. D. Balyabina, V. V. Slepysheva, A. V. Kozlov):

children: newborns - 250

from one year to 9 years - 350
from 10 to 14 years - 275 (for boys) and 280 (for girls)

boys from 15 to 19 years old - 155
girls from 15 to 19 years old - 150
adults: from 20 to 24 years old - 90 (m) and 85 (f)

from 25 to 34 years old - 95 (m) and 85 (f)
from 35 to 44 years old - 105 (m) and 95 (f)
from 45 to 54 years old - 120 (m) and 100 (f)
from 55 to 64 years old - 135 (m) and 110 (f)
from 65 to 74 years old - 95 (m) and 85 (f)
over 75 years old - 190 (m) and 165 (w)

According to the methodology used in the Invitro laboratory, the following values of alkaline phosphatase activity (in units/l) are considered normal (reference):

children under one year: 150–507
boys from one to 12 years old and girls from one to 15 years old: 0–500
male patients from 12 to 20 years: 0–750
Male patients over 20 years of age and female patients over 15 years of age: 40–150

An increase in alkaline phosphatase activity is possible in a variety of diseases and conditions (bone tissue pathologies with increased osteoblast activity or bone tissue breakdown, Paget's disease, osteomalacia, Gaucher's disease with bone resorption, primary or secondary hyperparathyroidism, rickets, fracture healing, osteosarcoma and metastases of malignant tumors in bone, liver cirrhosis, necrosis of liver tissue, primary hepatocarcinoma, metastatic liver cancer, infectious, toxic and drug-induced hepatitis, sarcoidosis, liver tuberculosis, intrahepatic cholestasis, cholangitis, bile duct and gallbladder stones, biliary tract tumors, cytomegaly in children, infectious mononucleosis , heart attack of the lung or kidney, insufficient amounts of calcium and phosphates in food). In addition, the cause of increased alkaline phosphatase activity occurs in premature infants, children during a period of rapid growth, in women in the last trimester of pregnancy and after menopause.

Also increases the activity of alkaline phosphatase by taking various drugs, including “gastroenterological”: itopride (growth spurt in adolescents

pregnancy (III trimester)

A decrease in the activity of alkaline phosphatase is possible with disorders of bone growth: with an excess of vitamin D and a lack of vitamin C, kwashiorkor, decreased thyroid function (hypothyroidism, myxedema), deficiency of magnesium and zinc coming from food and in old age with osteoporosis.

Hypophosphatasia

Hypophosphatasia is a rare progressive hereditary metabolic disease caused by alkaline phosphatase deficiency, which occurs due to a mutation in the gene encoding the nonspecific tissue isoenzyme of alkaline phosphatase. Deficiency of alkaline phosphatase activity in the blood serum leads to hypomineralization, extensive disorders of the skeletal bones and other multiple organ complications. A promising enzyme preparation is considered the only drug for the treatment of hypophosphatasia

Biochemical processes in living organisms occur with the help of enzymes. The latter play an important role in metabolism at the cellular level. Changes in their activity are a sign of a number of diseases. Therefore, it is so important to know what alkaline phosphatase in the blood (ALP) is and what its normal level is.

The content of enzymes of this group is determined in the tissues and liquids of not only humans, but also animals, plants, and microorganisms.

What you need to know about ALP

The group of most studied enzymes includes phosphatases, alkaline and acidic. They are widespread, but have differences in their properties.

Alkaline phosphatase is most active when the pH of the environment is between 8.4 and 9.4. This is typical for the epithelium of the small intestine, kidneys, liver, bones, and white blood cells.

Bone tissue especially needs the enzyme, since it needs it for metabolic processes and calcium saturation.

Alkaline phosphatase group is secreted from those tissues that transport phosphorus. The level of the enzyme is not the same even in the same organ or fluid.

A group of phosphatases is synthesized by osteoblasts - cells that participate in the construction of bone tissue. And for the synthesis of isoenzymes, phosphoric acid is required.

There is an absence of phosphatase in muscle tissues and mature connective tissues; its amount is minimal in the cells of the walls of blood vessels and hyaline cartilage of the nose, larynx, trachea and bronchi.

Changes in the activity of the phosphatase group depend on hormonal factors and stress. Enzyme levels differ in people belonging to different sexes and of different ages.

In men, the rate is 20-30 percent higher than in women. But an increase in phosphatase units is found in the blood of pregnant women. What does it mean? It’s okay, the embryo’s systems are just developing normally.

The ALP indicator is used in the diagnosis of diseases associated with the functions of the liver and bone apparatus.

Enzymes are active in rickets, osteogenic sarcoma, tuberculosis, diabetes, when phosphorus-calcium metabolism is impaired.

When the rate is low, hereditary diseases that are accompanied by skeletal abnormalities are diagnosed.

Indications for tests and performance

Blood chemistry must be assessed to determine the level of alkaline phosphatase activity. The study is carried out in a laboratory setting. They are sent for an alkaline phosphatase blood test in cases where there is a suspicion of:

pathological process in the liver and kidneys;
cholelithiasis;
damage to bone tissue;
pathologies of the lymphatic or circulatory system caused by infections;
malignant formation.

During pregnancy, blood tests for alkaline phosphatase are also needed.. Biochemical analysis is necessary to evaluate therapeutic measures and before surgery.

Before donating blood for analysis, the patient must:

Avoid eating eight hours before the procedure;
do not drink alcoholic beverages for two days;
temporarily suspend drug treatment and physical therapy sessions;
Do not undergo examinations using an X-ray machine:
Avoid heavy physical work and sports.

It is subject to analysis, so five to ten milliliters of blood will be required to assess enzyme levels. Fluid is collected in the morning from the ulnar vein.

Research results and their interpretation

Enzyme activity is determined by colorimetry. By adding certain reagents to the blood serum, reliable data are obtained on the number of phosphatase units in the tissues of the liver, bones, and placenta.

To measure the level of isoenzymes, the system of international units is used, the calculation is per liter of biological fluid.

Norm

The assessment of alkaline phosphatase concentration in a biochemical blood test occurs in accordance with the norm of its content:

in newborns - 250 units per liter;
for children from one to nine years old - 350;
from ten to fifteen - 280;
up to nineteen years of age, 150 units are considered the norm;
in adult males the figure varies from 85 to 145;
The norm for women is 20-25 units lower.

The normal blood level in older men reaches 195 units. The differences among adults are due to the fact that the transition to normal concentration in the stronger sex lasts until the age of 30. At this time, bone tissue already reduces the production of phosphatase.

For pregnant women, the normal level is from 25 to 126 units. The results of the analysis are interpreted by specialists, and not by the patient himself.

Sometimes high enzyme activity in women is associated not only with pregnancy, but also with the use of oral contraceptives.

An excessively high rate indicates complications during pregnancy in the second and third trimester - preeclampsia.

Toxicosis is accompanied by edema, nervous system disorders, and arterial hypertension.

You should not rely on the results of isoenzyme levels in diagnosis. To accurately determine the pathological condition, additional testing is carried out.

Reasons for increased phosphatase activity

More often, blood tests show an increase in alkaline phosphatase. Less often there is a reduced level.

The increase in units is due to:

presence of cancer;
liver damage;
osteoporosis;
rickets;
chronic alcoholism;
sepsis;
kidney infarction;
infectious damage to the lymph nodes, liver, spleen - mononucleosis;
disease of bone structures - Paget's disease.

Alkaline phosphatase activity is increased in case of poisoning - both food and alcohol. After a fracture, when the bones begin to heal, high levels of alkaline phosphatase are also determined. Many types of tumors in the human body affect the level of enzymes in the blood.

Liver diseases cause both an increase in alkaline phosphatase and a low concentration of urea in the blood, and an increase in cholesterol. And bone disease shows increased levels of globulins and erythrocyte sedimentation rate. An additional study will provide a complete picture of the disease and disorder.

Heart failure is the cause of many liver dysfunctions. In this case, phosphatase will also be increased.

How to reduce the rate

Since an increased level of phosphatase enzymes is associated with diseases of the bones, blood, and excretory system organs, treatment should be aimed specifically at eliminating pathological conditions.

If the increase process is physiological, then special methods to reduce ALP are not used.

You can reduce the activity of alkaline phosphatase:

giving up alcohol and cigarettes;
eating foods rich in phosphorus and calcium;
taking medications as prescribed by a doctor;
undergoing preventive examinations on time.

A properly selected diet is beneficial for patients with elevated phosphatase levels. A menu without fatty foods, smoked foods, sour fruits and vegetables, and fried foods will lead to the level of enzymes in the blood returning to normal.

Why is alkaline phosphatase activity reduced, what to do

The reasons for the decrease in the level of enzymes in the blood lie in a deficiency of vitamins C and group B, and a lack of zinc. This is where anemia develops. They are cured with iron and ascorbic acid preparations.

Signs of vitamin deficiency and scurvy can be easily identified by bleeding gums, tooth loss, and hemorrhagic rash.

Diet plays a major role in treatment. It is based on sources of vitamin C.

Congenital disease (hypophosphatasia) is determined by bone deformations, flaccid and flabby skin. The pathological form is based on a low level of alkaline phosphatase in the blood.

Often newborns with this disease die, and adults suffer from various bone deformities of the chest and feet. Patients experience frequent bleeding.

Lack of kwashiorkor protein in the body leads to severe dystrophy. Pathology occurs in children under five years of age when they do not receive enough protein. Their blood levels of glucose and cholesterol are reduced. Determine lack of potassium, magnesium. Phosphatase activity is also greatly reduced.

Only nutritional correction will bring the child’s condition back to normal. From the first days of therapy, medications containing the necessary elements, vitamins A and B, are prescribed.

Cottage cheese, foods rich in amino acids and protein are included in the diet. Of the fats, preference is given to vegetable ones, which are better absorbed.

Hypothyroidism, a hormonal disorder, is associated with insufficient thyroid function. It develops more often in women against the background of diseases of other organs and systems.

Therapy for hormonal imbalance is aimed at restoring the functioning of the thyroid gland.

To increase iodine levels, patients' menus include foods such as seaweed, chicken, milk, and cheese. Hormone levels are brought back to normal with thyroid medications.

Low ALP levels in pregnant women: consequences and treatment

If a decrease in the indicator is found in pregnant women, it is usually a symptom of placental insufficiency.

The danger of the pathological condition is that it leads to the death of the newborn or damage to the central nervous system of the fetus.

Placental insufficiency is considered a consequence of complications during pregnancy.

Health problems arise due to infections of the genital organs, incompatibility of mother and fetus according to the Rh factor.

If the expectant mother suffers from diabetes, heart failure, or pyelonephritis, then the alkaline phosphatase level in the blood will be low. Biochemical blood test changes under the influence of poor nutrition and smoking.

When alkaline phosphatase in the blood is reduced during pregnancy, a comprehensive diagnosis is carried out. After identifying the causes of insufficiency, the pregnant woman is prescribed physiotherapy aimed at improving the blood supply to the placenta and electrical relaxation of the uterus.

If the patient is diagnosed with heart and vascular diseases, diabetes mellitus, then appropriate treatment is prescribed.

As for drug therapy, the emphasis is on reducing the concentration of homocysteine in the blood with the drug Angiovit.

Vasodilators such as Trental reduce resistance in blood vessels. In the presence of diabetes mellitus, Heparin, Fraxiparine, and acetylsalicylic acid are used in the treatment.

Although pregnancy rarely occurs when a woman has hypothyroidism, a decrease in hormones produced by the thyroid gland occurs during pregnancy.

And this is dangerous because irreversible processes can occur in the embryo, leading to deformities.

During pregnancy, it is important for women to do biochemical blood tests on time to determine the alkaline phosphatase level. Timely restoration of its level will help the child to be born healthy.